AVMA Answers: Pharmaceutical compounding

What are the legal requirements for the use of compounded drugs?

Generally, the federal regulations require that, for a drug to be compounded legally, a valid veterinarian-client-patient relationship must exist, the health of the animal has to be threatened, and no FDA-approved drug is available that could be used per the label or in an extralabel manner to treat that animal effectively. Human food safety has to be ensured, and labeling and record-keeping requirements must be met.

And it's also important for veterinarians to learn how compounding is regulated by their states by contacting their state board of pharmacy.

When is it appropriate to use a compounded drug?

That will depend on the species being treated. For nonfood animals, veterinarians should first reach for an FDA-approved animal drug or, if none is available, an FDA-approved drug labeled for human use.

If there is no FDA-approved drug that could be modified to meet a nonfood animal patient's particular medical need, veterinarians can prepare a drug through compounding in their clinic or prescribe a drug to be compounded at a pharmacy. Compounding from raw pharmaceutical ingredients is not a legal activity, according to FDA regulations, but the agency does recognize that sometimes this is medically essential and has been willing to use enforcement discretion.

Veterinarians working with food animals should first look for an FDA-approved animal drug they can use per the label. If one is not available, AMDUCA allows veterinarians to turn to extralabel use of an animal drug.

If extralabel use of an animal drug is not an option, veterinarians can use drugs approved for use in humans or nonfood animals, but only if food safety can be ensured. Only in rare instances can compounded medications be used in food animals. Cost and convenience are not viable reasons. A compounded drug can be considered for a food animal only if there are no other options for properly treating that animal's disease and food safety is ensured.

Veterinarians must not allow a treated animal to enter the food chain unless adequate scientific evidence exists to indicate a proper withdrawal interval. Certain drugs are prohibited from being used in food animals. Specific guidance is available in the FDA's Animal Medicinal Drug Use Clarification Act regulations and Compliance Policy Guide on Compounding of Drugs for Use in Animals.

What would be the difference if a veterinarian were to use a mimic compound instead of an approved drug?

Production or use of a mimic is piracy. A mimic is a compounded drug that was produced to look like an FDA-approved drug. So that's going around the FDA approval process.

It's likely that a mimic has been made from raw pharmaceutical ingredients that have not been approved by the FDA, and there is no assurance of safety or efficacy.

Is there evidence that drugs compounded from bulk substances have been harmful?

Bulk substances are non-FDA-approved substances that are purported to contain a needed active ingredient. It is important for veterinarians to understand that the term "bulk" does not refer to the quantity of the drug being compounded; it refers to the fact that the drug is compounded from unapproved substances manufactured in bulk.

The 21 polo ponies that died in April in Florida were reportedly treated with a compounded drug similar to a product commercially available outside the U.S. Specifically, it was reported in the news that the product was meant to act similarly to Biodyl, that it was compounded from a bulk substance, and that it was prescribed for these ponies.

It's important that veterinarians know that, when they compound drugs, they are responsible for the safety and efficacy of the compounded drug. Veterinarians should also communicate to clients that compounding a drug could have an impact on how well that drug works.

The AVMA has more information on veterinary drug compounding at www.avma.org. At the top of the page, click on "Issues," scroll down to "Drugs," then click on "Compounding in your practice."

The FDA also has information available at www.fda.gov. Click on "Animals & Veterinary," then "Resources for You," then "FDA and the Veterinarian," and last, on "Compounding of Animal Drugs."